Press attachment



Jan. 6, 1959 B. ZALOZECKY 2,867,002

PRESS ATTACHMENT Filed Jan. 30, 1957 5 Sheets-Sheet 2 Lea IN VEN TOR.

United States Patent PRESS ATTACHMENT Bogdan Zalozecky, Vienna, Austria,assiguor t0 Fa. Gassareck, Vienna, Austria Application January 30, 1957,Serial No. 637,194 Claims priority, application Austria February 1, 1956Claims. 01. 18-16) Presses for the manufacture of hollow bodies of mold-In all these presses, driving means, consisting of pivoted levers,eccentrics or control cams, or hydraulic cylinders disposed in thedirection of movement of the press jaws, are provided for moving thepress jaws and are incorporated in the overall construction of thepress; these driving means form part of the press and are so complicatedin most cases that their assembly and maintenance require considerableadditional labor.

The invention is based on the suggestion to eliminate that disadvantagein that a simple press, which is either provided with a stationary ramand an upwardly movable platen, or with a movable ram and a stationaryplaten, is constructed with an attachment whereby press jaws having eachthe size of a side wall of the molding can be moved simultaneouslyagainst the ram by the upwardly movable platen or the lowerable ram. I

According to the invention that suggestion is realized in that astationary block having two interconnected bores disposed at rightangles .to each other is associated with each press jaw and a piston isliquid-tightly guided in each of said bores; thehorizontal one of thesepistons is firmly connected to the press jaw associated therewithwhereas. the upwardly extending, vertically displaceable piston servesas a driving piston and is adapted to be automatically coupled to acontrol device for the last part of the stroke of the platen or ram,which control device is attached to the cross-head of the press andengages the driving piston in the pushing and pulling directions;

said control devices push the driving pistons forwardly into the boresto pressurize the liquid in the bores and 'at the beginning of thelowering movement retract the driving pistons for pressure relief.

Such an attachment can be mounted in the case of need on any mechanicalor hydraulic press and can be 'removed'the'refrom because it consists ofa few elements, which are combined as a unit and require only littlelabor for manufacture and maintenance while ensuring a perfect and quickoperation in the molding of difiicultly moldable material which isunable to rise. Cornered and round hollow bodies can be quickly andperfectly made with such an attachment.

An embodiment of the press attachment according to the invention isshown diagramatically and by way of example in the drawing. Fig.1 showsa hydraulic press having a vertically movable platen together with theatplan view of the press platen and attachment with the til) tachment ina partly sectional elevation. Fig. 2.is a top ram shown incross-section. Fig. 3 shows a driving piston of one of the blocks inconjunction with a stationary stop in the end position before the upwardmovement of the platen. Figs. 4 and 5 are sectional elevations showing apress having a vertically movable ram before and after the pressingstroke.

The press consists of a base 2, which comprises the press cylinder 1 andcarries by means of columns 3 a cross-head 4, to which the depending ram5 is affixed. The press cylinder contains the pressure piston 6, whichcarries the platen 7 at its upper end. The platen 7 carries theattachment, which has a separate baseplate 8, which can be rigidly anddetachably connected to the platen 7, e. g., by means of screws 9.Depending on the shape of the molding, which consists, e. g., of a roundor fourcornered, open-topped container, and which is to be made fromdifficultly moldable material, e. g. of a finegrained granulatedsubstance, the baseplate 8 carries four guide blocks 10, which have theshape of right-angled stops and are adjustable towards or away from thecenter of the ram and can be locked in position by fixing screws 13adjustable in slots 11 of the block and slots 12 of the baseplate 8.Thus the guide blocks 10 can be adjusted to the desired volume of themolding. The

corners of the guide blocks 10 are preferably'ground at an obtuse angleto leave between themselves and the edge of the ram a hollow space forthe material of the molding. These four guide blocks 10 form with theiroutside surfaces the slideway for the press jaws 14, which are used toshape the walls of the molding and whose size corresponds to that of aside wall of the molding; these press jaws 14 are slidable parallel tothemselves between the guide blocks 10 on the baseplate 8 in thedirection toward the ram 5.

Each of the press jaws 14 has a screw bolt 15, which projects at rightangles from the jaw and on which a cap nut 16 can be screwed, which isfirmly connected to a piston 17. The screw bolt 15 is axially adjustablerelative to the press jaw 14 and can be fixed in position. The baseplate8 carries blocks 18 in a number equal to that of the press jaws 14.These blocks 18 are rigidly gether a single pressure space, which isfilled with a liquid,

e. g. with lubricating oil. The piston 17 of each press jaw is aliquid-tight fit in the horizontal bore of each block 18 whereas adriving piston 20 is aliquid-tight fit in the vertical bore and extendsto some extent above the block 18. That driving piston cooperates with astop bolt 21, which is rigidly attached to the cross-head 4 and is alsoadjustable in height by means of an adjusting nut 22. The driving piston29 and the appertaining stationary stop 21 are coaxially disposed and inthe initial position of the platen 7 their end faces are a distance aapart from each other; that distance a is somewhat smaller 'than thedistance [1 from the end face 23 of the ram to the surface of thebaseplate 8. The driving piston 20 has near its to an annular groove 25(Fig. 3) and the stop 21 is provided with two pawls 26, which protrudefrom its end face and are pivoted on pins and held in their catchingposition by an annular spring 27. Upon engagement between the end facesof the stop 21 and of the driving piston 20 these pawls 26 fall into theannular groove 25 of the driving piston to hold the latter against thestop 21. Each block 18 comprises also an automatic release for thedriving piston 20. That release consists of a sleeve 28, whichconcentrically surrounds the driving piston 20 and whose lower end isafiixed to the block 18, whereas its other end has a radially inwardlydirected edge bead 29, which during the lowering of the platen 7, i. e.,after the molding has-been shaped, strikes at a predetermined releasetime against extensions relieved from pressure.

30 of the pawls 26, whereby the latter are simultaneously moved out oftheir engaging position and the driving piston 20 is automaticallydisconnected from the stop 21.

-Moreover,-slides 24 are mounted on the press jaw 14 and displaceableparallel to themselves at right angles to the ram 5. These slides arehorizontally movably disposed on the press jaws 14, e. g., with the aidof elongated slots and several screws extending therethrough, and eachslide can be maintained in a forward position by a leaf spring attachedto the guide block and-engaging the rear edge of the slide 24. Theseslides 24 serve to close the mold cavity at the top, at the upper edgeof the press jaws, so that the compressed material is confined also atthe top. As the press jaws 14 are pushed forward the slides 24willengage the ram 5 first and will beurged back by the latter againstthe action of the leaf springs 24a (Fig. 2) during the continued advanceof the .press jaws 14. This attachment has the following mode ofoperation: It may be assumed that the molding material which consists ofdifficulty moldable material, e. g. a fine-grained or granulatedsubstance, lies already on the baseplate 8 and fillscnly part of thespace enclosed by the press aws 1 4 and theguide blocks 10. Theplaten v7is lifted, e. g., by hydraulic means so that the ram 5 dips graduallymto the molding material to force the same partly against the press jaws14. Now the cavitysurrounding the ram -5 is-completely filled withmolding material. When the platen -7 has reached the elevation set bymeans of the stops 21 a11 driving pistons engage the stationary stops 21-and immediately pressurize the liquid which is contamed in the block18. That liquid transmits this pressure through the intermediary of thepistons 17 to the press jaws 14, which at a predetermined time begin toadvance simultaneously and uniformly towards the ram 5 penetrating fromabove into the molding material, whereby the latter is compressed andshaped simultaneously from all sides. The slides 24 confine the mold cavty at the top and provide a perfect closure of the mold At the end ofthe press stroke the drying of the molding is accelerated by means ofhigh-frequency current so that it can be performed in a period amountingto between some seconds and a few minutes, depending on the thickness ofthe molding. For this purpose the rain 5 is electrically insulated fromthe cross-head 4 by an insulating layer 5a and is connected to oneelectrical conductor, whereas the platen 7 is connected for a shortperiod to the second high-frequency conductor.

After the molding has been dried and hardened the platen 7 is lowered.At the beginning of that lowering movement the driving pistons 20 areheld in place by the pawls 26, whereby the press jaws 14 are immediatelyAs the lowering of the platen 7 continues the pressure is furtherreduced in the space -19-of the blocks 18 and causes the pistons -17andthe press jaws 14 to move awayfrom the molding, where- :UPOH the-bead 29effects release ofpistons 20, by pawls-26. The molding is withdrawnautomatically by the slides 24 from the exposed ram 5. These slides moveaway from the ram 5 only after the press jaws 14 have performed a returnmovement-corresponding to the length of their elongated slots.

Since-the ram 5 as well as the, press jaws 14 can be replaced or can beprovided with mountings 31 of differ- =ent thickness, as desired, thatattachment enables considerable variations with respect to the size,shape and decoration of the hollow body to be molded.

The same attachment can be used with like success on presses havingastationary platen and a vertically movable ram. An example is shown inFigs. 4 and 5.

It comprises a rigid platen 7 provided with the attachment which hasbeen described hereinbefore, comprising the baseplate 8, theguide blocks10, the press jaws 14,

the blocks 18 and the driving pistons 20. In the cavity confined by thepress jaws-14, a core member 32 is disposed, the size and shape of whichdetermine the cavity of the hollow body to be molded. Instead of a ram,a vertically movable press plate 5 is provided, whose pressing surfacecorresponds in size and shape to the bottom surface of the hollow bodyto be made. The cover slides 24 are also provided on the press jaws,with screws extending through elongated slots, and have the samefunction as in the first embodiment. However, in this case the slidesare of angular shape and engage the press plate with one leg ofthe'angle.

The press operation is the same as described hereinbefore becausetogether 'with the press plate the control stops 21 are moved to engagethe driving pistons 20 so that all :press jaws are simultaneously movedagainst the core member.

This attachment has the advantage that the core member 32 as well as thepress jaws 14 may be provided with grooves or rebates or ornament orsimilar decoration desired-on the finished lrollow body. lnithiscasehighfrequency drying is also possible and mountings may be employed 1 tovary the size and-form.

1 claim:

v l. A molding press comprising, in combination, afirst press member anda second press member, one press member being movable in one directiontoward and away from the other press :member between a retractedposition and an advanced operativeposition; a set of lateral pressjawsmounted on said first press member, each press jaw being movable inadirection transverse to said one direction between an outer retractedposition and an inner advanced position, said press members and saidpress jaws defining in said advanced'positions a pressure space formolding-an article of granulated material; a

set ofstationary cylinder blocks on-said first press mem- 35 jaw and asecond cylinderportion extending in said one direction; a set-ofpress-pistons respectively located in said first cylinder portions andconnectedzto said press jaws, and a set ofdrivepistonsrespectively'located in said second cylinder-portions; asetofcoupling means mountedon said second press-member and respectivelyassociated with said drive pistons'for coupling said second press-memberto said drive-pistons infan intermediate position ofsaid one pressmember duringadvance movement of the same so that during further advancemovement' of said one press'membe r, said drive pistons .and said'cylinder blocks move relative to each other in said one direction-andetfect inward' movement of said press pistons "and thereby movements ofsaid press jaws from saidouter retracted positions to saidinnereadvancedpositionsfandwhereby during the return movementof said one press memberfrom said advanced position, *said "drive pistons-and cylinder-blocksmove relativexto each fother toeffectwithdrawal'of said presspistonsandsaid press jaws to said retracted positions; and releasingmeans on said first press member for engaging and releasing saidcoupling means in another intermediate position of said one press'memberwhen'said press-jaws-arrive insaid retracted positions of -the same.

2. A molding press comprising, in combination, a first press member anda second-press-member,=-one press member being movable in'one directiontoward and away from the other press member-betweena' retracted positionandan advanced operative position; a set of lateral "pressjaws-mounted'on said first-press member, each press jaw being movable ina direction transverse to said one direction between an outer retractedposition and an inner advanced position, said press members .and saidpress jaws defining in said advanced positions: a pressure space formolding an article of granulatedmaterial;1a set of stationary cylinderblocks onsaid. firstspresszmemher, each cylinder block being associatedwith one of said press jaws, each cylinder block being formed with aclosed cavity adapted to contain an operating liquid and including afirst cylinder portion extending in direction of said transversemovement of the associated press jaw and a second cylinder portionextending in said one direction; a set of press pistons respectivelylocated in said first cylinder portions and connected to said'pressjaws, and a set of drive pistons respectively located in said secondcylinder portions, each of said drive pistons having a recess; a set ofcoupling means mounted on said second press member and respectivelyassociated with said drive pistons for coupling said second press memberto said drive pistons in an intermediate position of said one pressmember during advance movement of the same so that during furtheradvance movement of said one press member, said drive pistons and saidcylinder blocks move relative to each other in said one direction andeffect inward movement of said press pistons and thereby movements ofsaid press jaws from'said outer retracted positions to said inneradvanced positions, and whereby during the return movement of said onepress member from said advanced position, said drive pistons andcylinder blocks move relative to each other to eifect withdrawal of saidpress pistons and said press jaws to said retracted positions, each ofsaid coupling means including a member fixedly secured to said secondpress member and abutting on the end of the associated drive piston insaid intermediate position of said one press member, and spring loadedcatch means engaging said recess in the respective associated drivepiston in said intermediate position of said one press member; andstationary releasing means on said first press member, and including acam means engaging said catch means in another intermediate position ofsaid one press member for moving saidcatch means to a releasing positionreleasing the associated drive pistons when said press jaws arrive insaid retracted positions of the same.

3. A molding press comprising, in combination, a stationary press ram; apress member movable :in vertical direction toward and away from saidpress ram between a retracted position and an advanced operativeposition; a set of lateral press jaws mounted on said press member, eachpress jaw being supported for horizontal movement between an outerretracted position and an inner advanced position, said press ram,movable press member and said press jaws defining in said advancedpositions at pressure space for molding an article of granulatedmaterial; a set of cylinder blocks secured to said movable press member,each cylinder block being associated with one of said press jaws andlocated outwardly of the same, each cylinder block being formed with acavity adapted to contain an operating liquid and including a verticalcylinder portion, and a horizontal cylinder portion extending in thetransverse direction of movement of the associated press jaw; a set ofpress pistons respectively located in said horizontal cylinder portionsand connected to said press jaws, and a set of drive pistons located insaid vertical cylinder portions; 'a set of coupling means fixedlysecured to said press ram respectively aligned in vertical directionwith said drive pistons for coupling said press ram to said drivepistons in an intermediate position of said press member during advancemovement of the same so that during the last part of the advancemovement of said press member, said drive pistons are moved into saidvertical cylinder portions and effect inward movement of said presspistons and thereby movements of said press jaws from said outerretracted positions to said inner advanced positions, and whereby duringthe first part of the return movement of said press member from saidadvanced position, said drive pistons are retracted and effectwithdrawal of said press pistons and of said press jaws to saidretracted positions; and a set of stationary releasing means secured tosaid cylinder blocks and engaging said coupling means in anotherintermediate position of said press member during return movement of thesamev for releasing said coupling means when said press jaws arrive insaid retracted positions of the same.

4. A molding press, comprising, in combination, a stationary press ram;a press member movable in vertical direction toward and away from saidpress ram between a retracted position and an advanced operativeposition; a set of lateral press jaws mounted on said press member, eachpress jaw being supported for horizontal movement between an outerretracted position and an inner advanced position, said press ram,movable press member, and said press jaws defining in said advancedpositions a pressure space for molding an article of granulatedmaterial; a set of cylinder blocks secured to said movable press member,each cylinder block being associated with one of said press jaws andlocated outwardly of the same, each cylinder block being formed with acavity adapted to contain an operating liquid and including a verticalcylinder portion, and a horizontal cylinderportion extending in thetransverse direction of movement of the associated press jaw; a set ofpress pistons respectively located in said horizontal cylinderportionsand connected to said press jaws, and a set of drive pistonslocated in said vertical cylinder portions, each of said drive pistonshaving an upper portion projecting out of said vertical cylinder portionand being formed with an annular recess; a set of coupling means fixedlysecured to said press ram respectively aligned in vertical directionwith said drive pistons for coupling said press ram to said drivepistons in an intermediate position of said press member during advancemovement of the same so that during the last part of the advancemovement of said press member, said drive pistons are moved into saidvertical cylinder portions and effect inward movement of said presspistons and thereby movementsof said press jaws from said outerretracted positions to said inner advanced positions, and whereby duringthe first part of the return movement of said press member from saidadvanced position, said drive pistons are retracted and effectwithdrawal of said press pistons andof said press jaws to said retractedpositions, each of said coupling means including springloaded catchmeans engaging said annular recess in the associated drive piston insaid intermediate position for coupling to said drive pistons to saidpress ram; and a set of stationary releasing means secured to saidcylinder blocks, each releasing means including a sleeve secured to oneof said cylinder blocks and surrounding said catch means in saidintermediate position, each sleeve having an annular bead engaging saidcatch means in another further retracted intermediate position of saidpress member for releasing said catch means from said associated recesswhen said press jaws arrive in said retracted positions or" the same.

5. A molding press as set forth in claim 4 and including guide blockshaving surfaces defining guide ways for said press jaws, said guideblocks being detachably secured to said movable press member.

6. A molding press as set forth in claim 4 wherein said coupling meanseach include a member fixedly secured to said press ram and abutting onthe upper end of the associated drive piston in said intermediateposition of said press member, and wherein said catch means include aplurality of hook-shaped pawls pivotally mounted on said last mentionedmember, and an annular spring surrounding and engaging said pawls.

7. A molding press as set forth in claim 1 and including a set of slidesslidably mounted on said press jaws, respectively; spring means urgingsaid slides in inward direction, and lost-motion means connecting saidpress jaws with the associated slides for retracting the same, saidslides being adapted to engage the edge of a molded object duringretraction of said press member.

8. A molding press as set forth in claim 1 wherein said second pressmember is movable and constitutes said movable press member.

9. A molding press comprising, in combination, a first press member anda second .press member, one press member beingmovable in one directiontoward :nad away from the other press member between a retracted.position and an advanced operative positionya .set of lateral pressjaws mounted on said first pressmember, each press jaw being movable ina direction transverse to said one direction between an outer retractedposition and an inner advanced position, said press members and saidpress jaws defining in said advanced positions a pressure space formolding an article of granulated material; hydraulic operating meansmounted on said first press member and being connected to said pressjaws for actuating the same; and coupling means mounted on said secondpress member and engaging said hydraulic operating means in anintermediate position of said one press member during advance movementof the same for actuating said bydraulic operating means so that duringfurther advance movement of said one press member said press jaws aremoved from said outer retracted positions to said inneradvancedpositions and whereby during the return movement of said onepress member from said advanced position said press jaws are moved tosaid retracted posi tions; and a set of stationary releasing means onsaid first press member for engaging and releasing said coupling meansin another intermediate position of said one press member when saidpress jaws arrive in said retracted positions of the same.

10. A molding press comprising, in combination, a stationary press ram;a press member movable in vertical direction toward and away from saidpress ram between a retracted position and an advancedoperativeposition; a set of lateral press jaws mounted on said pressmember, each press jaw being supported for horizontal movement betweenan outer retracted position and an inner advanced position, said pressram, movable press memher, and said press jaws defining in said advancedpositions va pressure space for molding an article of granulatedmaterial, said press ram being surrounded by said press jaws in saidadvanced position of said movable press member and having airee andspaced a short distance from said movable press member in said advancedposition of the same; a set of cylinder blocks secured to said movablepress member, each cylinder block being associated with one of saidpress jaws and located outwardly of {the same, each cylinder bloclrbeing formed with a cavity adapted to contain an operating liquid andincluding ,a vertical cylinder portion, and a horizontal cylinderportion extending in the transverse direction of movement oftheassociated press jaw; a set of press pistons respectively located insaid horizontal cylinder portions and connected :to said press jaws, anda set of drive pistons located in said vertical cylinder portions; a setof .cfoupling'means :fixedly secured to said press ram respectivelyaligned in vertical direction with said drive pistons for couplingsaidpress ram to said drive pistons in;an intermediate position of'saidpress member during advance movement of the same so that during the lastpart of the advancemovement of said press member, said drive pistons aremoved into said vertical cylinder portions and effect inward movement ofsaid press pistons and thereby movements of said press jaws from saidouter retracted positions to said inner advanced positions, and

whereby during thefirst part of the return movement of said press memberfrom said advanced position, said drive pistons are retracted and effectwithdrawal of said press pistons and of said press jaws to saidretracted positions; and a set of releasing means secured to saidcylinder blocks and engaging said coupling means in another intermediateposition of said press member during return movement of the same forreleasing said coupling means when saidpress jaws arrive insaidretracted positions of the same.

:Willard Sept. 7, 1920 Amigo July 27, 1948

